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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Linijski model interakcije vode i nanosa u mreži prirodnih vodotoka / A one-dimensional model for flow and sediment interaction in a looped network ofnatural watercourses

Isić Mirjana 17 July 2014 (has links)
<p>U radu su prikazani razvoj, testiranje, kalibracija i verifikacija linijskog modela neustaljenog tečenja vode i transporta nanosa u mreži prirodnih vodotoka.<br />Hidraulički model se zasniva na St. Venant -ovim jednačinama koje su diskretizovane primenom Preissmann-ove &scaron;eme. Za modelisanje transporta nanosa i deformacije korita je usvojen koncept koji daje mogućnost da se obuhvate oba vida<br />kretanja nanosa (suspendovanog i vučenog). Primenom pristupa aktivnog sloja su<br />definisani procesi razmene materijala između nanosa u suspenziji i nanosa u aktivnom sloju. Osnovne jednačine transporta nanosa i deformacije korita su rečene<br />primenom metode etapnog re&scaron;avanja čija primena rezultuje u dva uzastopna koraka, advektivnom i difuzionom koraku. Jednaˇcine advektivnog koraka su ređavane<br />metodom karakteristika, dok se za jednačine difuzionog koraka primenila CrankNicholson-ova &scaron;ema metode konaˇcnih razlika. Dobijene jednačine su dopunjene<br />sa dodatnim jednačinama kako bi se omogućilo modelisanje opisanih procesa u<br />granatoj mrezi otvorenih tokova. Izvedene jednacine su primenjene za formiranje<br />numerickog modela koji jeđvalitativno testiran na &scaron;ematskim primerima, a kvantitativni testovi su urađeni na realnom primeru. Za realan primer je izabrana deonica Dunava u Srbiji sa glavnim pritokama Savom i Tisom. Kako bi se definisala oblast koja će se koristiti za verifikaciju modela napravljen je detaljan pregled i sistematizacija postojećih merenja morfologije korita, nivoa, proticaja i koncentracija suspendovanog nanosa. Na osnovu ovog pregleda je definisana morfologija modelisane mreže tokova. Pri kalibraciji hidrauličkog modela su razmotrena dva pristupa,<br />kalibracija putem Manning-ovog koeficijenta zadatog kao funkcije od proticaja, i<br />kalibracija zadavanjem apsolutne hrapavosti, dok je verifikacija modela urađena<br />pu&scaron;tanjem simulacije od godinu dana i poređenjem rezultata proračuna sa merenjima. Kalibracija modela transporta je sprovedena za duži vremenski period kako bi se &scaron;to bolje opisale godi&scaron;nje varijacije koncentracije suspendovanog nanosa, a za verifikaciju modela je odabran petogodiˇsnji period tokom kojeg su upoređeni rezultati proracuna sa merenjima, čime je pokazano da razvijen model moze pouzdano da simulira procese strujanja vode i transprta nanosa u mreži otvorenih tokova.<br />&nbsp;</p> / <p>This work presents the development, evaluation, calibration and verification of a<br />one dimensional unsteady flow, sediment transport and bed evolution looped river<br />network model. The hydraulic model is based on the St. Venant&rsquo;s equations discretized using the Preissmann&rsquo;s scheme. The sediment transport and bed evolution<br />model implements a concept that differentiates sediment particles moving in the<br />form of suspended sediment, and near bed and bed sediment. Applying the active<br />layer concept the developed model includes definitions of the exchange mechanisms<br />between the suspended sediment and active layer material. The governing transport equations were solved using the split operator approach that resulted in two<br />successive steps, the advection and diffusion step. The advection step equations<br />were solved using the characteristics method, whereas the diffusion step equations<br />are discretized using the Crank-Nicholson&rsquo;s scheme. The obtained system of the<br />developed equations was complemented with additional equations in order to allow<br />sediment transport and bed evolution simulation in a looped river network. The<br />derived equations were applied to develop an open channel flow, sediment transport and bed evolution numerical model that was subjected to a series of schematic<br />tests and a real life situation simulation. The model&rsquo;s evaluation was conducted<br />by comparison of the simulation results with the available measurements. The presented work was complemented with an comprehensive overview of the existing<br />bathymetry, water level, discharge and suspended sediment concentration measurements in order to define the model&rsquo;s domain, initial and boundary conditions. The calibration of the hydraulic model was done by assigning the Manning&rsquo;s coefficient<br />as a function of the discharge. As a result of the exhausting requirements of this<br />approach, a second approach was considered, where the calibration is conducted by<br />changing the absolute roughness. The verification of the hydraulic model was done<br />by comparing the computed results of a one year flow simulation with the available<br />measurements. Since the agrement between the two was satisfying, the sediment<br />transport and bed evolution model was calibrated using a longer time interval in<br />order to better capture the annual variations of the suspended sediment. The calibrated model was employed for a long term sediment transport and bed evolution<br />simulation. The simulation results were compared with the existing measurements<br />confirming the developed model&rsquo;s reliability.</p>
42

Contribution to the Experimental Characterization and 1-D Modelling of Turbochargers for IC Engines

Reyes Belmonte, Miguel Ángel 07 January 2014 (has links)
At the end of the 19th Century, the invention of the Internal Combustion Engine (ICE) marked the beginning of our current lifestyle. Soon after the first ICE patent, the importance of increasing air pressure upstream the engine cylinders was revealed. At the beginning of the 20th Century turbo-machinery developments (which had started time before), met the ICE what represented the beginning of turbocharged engines. Since that time, the working principle has not fundamentally changed. Nevertheless, stringent emissions standards and oil depletion have motivated engine developments; among them, turbocharging coupled with downsized engines has emerged as the most feasible way to increase specific power while reducing fuel consumption. Turbocharging has been traditionally a complex problem due to the high rotational speeds, high temperature differences between working fluids (exhaust gases, compressed air, lubricating oil and cooling liquid) and pulsating flow conditions. To improve current computational models, a new procedure for turbochargers characterization and modelling has been presented in this Thesis. That model divides turbocharger modelling complex problem into several sub-models for each of the nonrecurring phenomenon; i.e. heat transfer phenomena, friction losses and acoustic non-linear models for compressor and turbine. A series of ad-hoc experiments have been designed to aid identifying and isolating each phenomenon from the others. Each chapter of this Thesis has been dedicated to analyse that complex problem proposing different sub-models. First of all, an exhaustive literature review of the existing turbocharger models has been performed. Then a turbocharger 1-D internal Heat Transfer Model (HTM) has been developed. Later geometrical models for compressor and turbine have been proposed to account for acoustic effects. A physically based methodology to extrapolate turbine performance maps has been developed too. That model improves turbocharged engine prediction since turbine instantaneous behaviour moves far from the narrow operative range provided in manufacturer maps. Once each separated model has been developed and validated, a series of tests considering all phenomena combined have been performed. Those tests have been designed to check model accuracy under likely operative conditions. The main contributions of this Thesis are the development of a 1-D heat transfer model to account for internal heat fluxes of automotive turbochargers; the development of a physically-based turbine extrapolation methodology; the several tests campaigns that have been necessary to study each phenomenon isolated from others and the integration of experiments and models in a comprehensive characterization procedure designed to provide 1-D predictive turbocharger models for ICE calculation. / Reyes Belmonte, MÁ. (2013). Contribution to the Experimental Characterization and 1-D Modelling of Turbochargers for IC Engines [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34777
43

Modellierung, Simulation und Bewertung parallel-hybrider Antriebskonfigurationen für dieselhydraulische Triebwagen im Nah- und Regionalverkehr

Kache, Martin 09 October 2014 (has links) (PDF)
Ausgangspunkt der Untersuchung ist die Frage, ob Hybridkonzepte auf hydrostatischer Grundlage eine realistische Alternative zu elektrohybriden Antriebskonfigurationen für Dieseltriebwagen sein können. Die Untersuchung dieser Fragestellung erfolgt mit Hilfe von Simulationsmodellen, die auf der 1-d-Simulationsumgebung Imagine.Lab AMESim beruhen. Zunächst wird die fahrdynamische und antriebstechnische Modellierung eines dieselhydraulischen Regionaltriebwagens unter Berücksichtigung einer energiesparenden Fahrweise dargestellt. Ausgehend von Massenbilanzen werden untereinander vergleichbare Hybridkonfigurationen auf hydrostatischer (Gasdruckspeicher), elektrostatischer (Doppelschichtkondensatoren) und elektrochemischer (Li-Ionen-Speicher) Basis entwickelt. Die Modellierung der hydraulischen und elektrischen Antriebsstränge wird eingehend diskutiert. Die abgeleiteten Hybridkonfigurationen werden anschließend bezüglich spezieller Fahrspiele und Betriebskonzepte detailliert untersucht, um auf dieser Grundlage günstige Parametrierungen der Systeme ableiten und die günstigste Betriebsstrategie identifizieren zu können. Anschließend wird eine umfangreiche Analyse des Verhaltens der verschiedenen Hybridkonfigurationen auf ausgewählten realen Nahverkehrsstrecken vorgenommen. Im Rahmen der durchgeführten Simulationen wird schließlich das Kraftstoffeinsparpotential in Abhängigkeit von Streckenprofil, Hybridkonfiguration und Zugart ermittelt und verglichen.
44

Analysis of Flash Flood Routing by Means of 1D - Hydraulic Modelling

Tesfay Abraha, Zerisenay 23 October 2013 (has links) (PDF)
This study was conducted at the mountainous catchment part of Batinah Region of the Sultanate of Oman called Al-Awabi watershed which is about 260km2 in area with about 40 Km long Wadi main channel. The study paper presents a proposed modeling approach and possible scenario analysis which uses 1D - hydraulic modeling for flood routing analysis; and the main tasks of this study work are (1) Model setup for Al-Awabi watershed area, (2) Sensitivity Analysis, and (3) Scenario Analysis on impacts of rainfall characteristics and transmission losses. The model was set for the lower 24 Km long of Al-Awabi main channel (Figure 13). Channel cross-sections were the main input to the 1D-Hydraulic Model used for the analysis of flash flood routing of the Al-Awabi watershed. As field measurements of the Wadi channel cross-sections are labor intensive and expensive activities, availability of measured channel cross-sections is barely found in this study area region of Batinah, Oman; thereby making it difficult to simulate the flood water level and discharge using MIKE 11 HD. Hence, a methodology for extracting the channel cross-sections from ASTER DEM (27mX27m) and Google Earth map were used in this study area. The performance of the model setup was assessed so as to simulate the flash flood routing analysis at different cross-sections of the modeled reach. And from this study, although there were major gap and problems in data as well as in the prevailing topography, slope and other Hydro Dynamic parameters, it was concluded that the 1D-Hydraulic Modelling utilized for flood routing analysis work can be applied for the Al-Awabi watershed. And from the simulated model results, it was observed that the model was sensitive to the type of Boundary Condition chosen and taken, channel cross sections and its roughness coefficient utilized throughout the model reach.
45

Observer-based engine air charge characterisation : rapid, observer-assisted engine air charge characterisation using a dynamic dual-ramp testing method

Schaal, Peter January 2018 (has links)
Characterisation of modern complex powertrains is a time consuming and expensive process. Little effort has been made to improve the efficiency of testing methodologies used to obtain data for this purpose. Steady-state engine testing is still regarded as the golden standard, where approximately 90% of testing time is wasted waiting for the engine to stabilize. Rapid dynamic engine testing, as a replacement for the conventional steady-state method, has the potential to significantly reduce the time required for characterisation. However, even by using state of the art measurement equipment, dynamic engine testing introduces the problem that certain variables are not directly measurable due to the excitation of the system dynamics. Consequently, it is necessary to develop methods that allow the observation of not directly measurable quantities during transient engine testing. Engine testing for the characterisation of the engine air-path is specifically affected by this problem since the air mass flow entering the cylinder is not directly measurable by any sensor during transient operation. This dissertation presents a comprehensive methodology for engine air charge characterisation using dynamic test data. An observer is developed, which allows observation of the actual air mass flow into the engine during transient operation. The observer is integrated into a dual-ramp testing procedure, which allows the elimination of unaccounted dynamic effects by averaging over the resulting hysteresis. A simulation study on a 1-D gas dynamic engine model investigates the accuracy of the developed methodology. The simulation results show a trade-off between time saving and accuracy. Experimental test result confirm a time saving of 95% compared to conventional steady-state testing and at least 65% compared to quasi steady-state testing while maintaining the accuracy and repeatability of conventional steady-state testing.
46

Teoria escalar-tensorial: Uma abordagem geométrica

Almeida, Tony Silva 29 July 2014 (has links)
Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-13T14:39:21Z No. of bitstreams: 1 arquivototal.pdf: 851323 bytes, checksum: 599a5da8bbbe70ff2f4ba121890878e2 (MD5) / Made available in DSpace on 2017-09-13T14:39:21Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 851323 bytes, checksum: 599a5da8bbbe70ff2f4ba121890878e2 (MD5) Previous issue date: 2014-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this cool thesis, we consider an approach to Brans-Dicke theory of gravity in which the scalar eld has a geometrical nature. By postulating the Palatini variation, we nd out that the role played by the scalar eld consists in turning the space-time geometry into a Weyl integrable manifold. This procedure leads to a scalar-tensor theory that di ers from the original Brans-Dicke theory in many aspects and presents some new features. We also consider the Weyl integrable geometry to investigate gravity in (2+1)-dimensions. We show that, in addition to leading to a Newtonian limit, WIST in (2+1) dimensions presents some interesting properties that are not shared by Einstein theory, such as geodesic deviation between particles in a dust distribution. Finally, taking advantage of the duality between the geometrical scalar-tensor theory and general relativity coupled with a massless scalar eld we study naked singularities and wormholes. / Esta tese trata de tópicos relacionados às teorias escalares-tensoriais e a geometria de Weyl integrável. Nossa abordagem será no sentido de indicar a geometria de Weyl integr ável como sendo um ambiente natural para a introdução de teorias escalares-tensorias. Nossa discussão será em torno da teoria de Brans-Dicke, considerada o protótipo das teorias escalares tensoriais, no entanto a discussão é facilmente estendida para essas versões mais gerais. Fazemos isso em dois momentos. Primeiro, indicando, no âmbito da teoria de Brans-Dicke, que na estrutura geométrica e de campos adotadas pela teoria existe uma relação estreita com a geometria de Weyl, inclusive associando o efeito descrito na literatura como "quinta força"(que violaria o princípio de equivalência) com o movimento geodésico da geometria de Weyl integrável, reformulando o postulado geodésico. E, num segundo momento, usando o método variacional de Palatini, acabamos por formular uma nova teoria escalar-tensorial, agora com ingredientes completamente geométricos, ambientada numa geometria de Weyl integrável. Estudamos ainda soluções no vazio do problema estático de uma distribuição de massa esfericamente simétrica, onde surgem objetos de interesse astrofísico como singularidades nuas e buracos de minhoca. Também formulamos a teoria conhecida por WIST (Weyl Integrable Spacetimes) em (2 + 1)D, o que resulta numa teoria consistente, não sofrendo das falhas associadas à teoria da relatividade geral nessa dimensionalidade
47

Mitigating Congestion by Integrating Time Forecasting and Realtime Information Aggregation in Cellular Networks

Chen, Kai 11 March 2011 (has links)
An iterative travel time forecasting scheme, named the Advanced Multilane Prediction based Real-time Fastest Path (AMPRFP) algorithm, is presented in this dissertation. This scheme is derived from the conventional kernel estimator based prediction model by the association of real-time nonlinear impacts that caused by neighboring arcs’ traffic patterns with the historical traffic behaviors. The AMPRFP algorithm is evaluated by prediction of the travel time of congested arcs in the urban area of Jacksonville City. Experiment results illustrate that the proposed scheme is able to significantly reduce both the relative mean error (RME) and the root-mean-squared error (RMSE) of the predicted travel time. To obtain high quality real-time traffic information, which is essential to the performance of the AMPRFP algorithm, a data clean scheme enhanced empirical learning (DCSEEL) algorithm is also introduced. This novel method investigates the correlation between distance and direction in the geometrical map, which is not considered in existing fingerprint localization methods. Specifically, empirical learning methods are applied to minimize the error that exists in the estimated distance. A direction filter is developed to clean joints that have negative influence to the localization accuracy. Synthetic experiments in urban, suburban and rural environments are designed to evaluate the performance of DCSEEL algorithm in determining the cellular probe’s position. The results show that the cellular probe’s localization accuracy can be notably improved by the DCSEEL algorithm. Additionally, a new fast correlation technique for overcoming the time efficiency problem of the existing correlation algorithm based floating car data (FCD) technique is developed. The matching process is transformed into a 1-dimensional (1-D) curve matching problem and the Fast Normalized Cross-Correlation (FNCC) algorithm is introduced to supersede the Pearson product Moment Correlation Co-efficient (PMCC) algorithm in order to achieve the real-time requirement of the FCD method. The fast correlation technique shows a significant improvement in reducing the computational cost without affecting the accuracy of the matching process.
48

DEVELOPMENT, DESIGN, AND CONSTRUCTION OF A HUMAN-BUILDING INTERACTIONS LABORATORY

Sourabh Deepak Yadav (12224741) 20 April 2022 (has links)
<div>The evolution of existing building construction is envisioned as modular construction. Instead of on-site construction, buildings can be assembled on-site using prefabricated modular elements. These modular elements could integrate intelligent building technologies to enable autonomous, occupant responsive, scalable, cost-effective, and sustainable features. On-site assembly of modular construction elements would offer better quality control, decrease material waste and resources, with more predictable schedules. These building elements would allow more cost-effective integration of new intelligent sensors, adaptive interfaces, renewable energy and energy recovery technologies, comfort delivery, and resiliency technologies, making high-performance buildings more affordable. To explore and evaluate these modular and intelligent comfort delivery concepts and advanced approaches for interaction with occupants, a new Human-Building Interactions Laboratory (HBIL) has been designed and is under development. The facility has a modular construction layout with thermally active panels, and the interior surface temperature of each panel can be individually controlled using a hydronic system. Such configuration allows us to emulate different climate zones and building type conditions and perform studies such as the effect of different kinds of active building surfaces on thermal comfort, localized comfort delivery, and occupant comfort control. Moreover, each panel is reconfigurable to investigate different interior surface treatments for thermal, visual, and acoustic comfort conditions. <br></div><div>In this MS thesis work, the overall design approach of the facility is presented. Development, experimental investigation of thermal performance, and aligned design modifications of a prototype thermo-active wall panel are explained in detail. Detailed development of a 1-D transient numerical model for the prototype wall panel and its tuning and validation are also presented. Furthermore, the design and installation plan of the hydronic system for the HBIL facility are also presented with an initial commissioning plan.</div>
49

Analysis of Flash Flood Routing by Means of 1D - Hydraulic Modelling

Tesfay Abraha, Zerisenay 17 September 2010 (has links)
This study was conducted at the mountainous catchment part of Batinah Region of the Sultanate of Oman called Al-Awabi watershed which is about 260km2 in area with about 40 Km long Wadi main channel. The study paper presents a proposed modeling approach and possible scenario analysis which uses 1D - hydraulic modeling for flood routing analysis; and the main tasks of this study work are (1) Model setup for Al-Awabi watershed area, (2) Sensitivity Analysis, and (3) Scenario Analysis on impacts of rainfall characteristics and transmission losses. The model was set for the lower 24 Km long of Al-Awabi main channel (Figure 13). Channel cross-sections were the main input to the 1D-Hydraulic Model used for the analysis of flash flood routing of the Al-Awabi watershed. As field measurements of the Wadi channel cross-sections are labor intensive and expensive activities, availability of measured channel cross-sections is barely found in this study area region of Batinah, Oman; thereby making it difficult to simulate the flood water level and discharge using MIKE 11 HD. Hence, a methodology for extracting the channel cross-sections from ASTER DEM (27mX27m) and Google Earth map were used in this study area. The performance of the model setup was assessed so as to simulate the flash flood routing analysis at different cross-sections of the modeled reach. And from this study, although there were major gap and problems in data as well as in the prevailing topography, slope and other Hydro Dynamic parameters, it was concluded that the 1D-Hydraulic Modelling utilized for flood routing analysis work can be applied for the Al-Awabi watershed. And from the simulated model results, it was observed that the model was sensitive to the type of Boundary Condition chosen and taken, channel cross sections and its roughness coefficient utilized throughout the model reach.
50

Modelling and analysis methodology of SI IC engines turbocharged by VGT

Gómez Vilanova, Alejandro 01 April 2022 (has links)
[ES] Se espera que la nueva generación de motores de encendido provocado represente la mayor parte del mercado en el contexto de la propulsión de vehículos con o sin hibridación. Sin embargo, la tecnología actual todavía tiene desafíos críticos por delante para cumplir con los nuevos estándares de emisiones de CO2 y contaminantes. Consecuentemente están surgiendo nuevas tecnologías para mejorar la eficiencia de los motores y que estos cumplan con las nuevas normativas anti-contaminación. Entre otras, una de las tendencias más seguidas en la actualidad es la reducción de tamaño de los motores, concepto conocido como "downsizing", bajo la técnica de la turbosobrealimentación. Las nuevas tecnologías de turbocompresores, como las turbinas de geometría variable (TGV), se empiezan a considerar para su aplicación en las exigentes condiciones de funcionamiento de los nuevos motores de encendido provocado. En este trabajo, a partir de datos experimentales obtenidos en la sala de ensayos del motor, se propone una metodología de calibración del modelo completo de motor 1-D: se realiza un análisis teórico dirigido a asegurar el control total sobre cualquier aspecto de la simulación. En otras palabras, el modelo de motor 1-D se ajustó completamente con respecto a los datos experimentales del motor. Además, se demuestra la necesidad del postprocesamiento y validación de datos experimentales relacionados con mapas de turbocompresores, ya que se requiere desacoplar fenómenos como la transferencia de calor y las pérdidas por fricción de los denominados mapas experimentales de turbocompresores. De acuerdo con esto, se presenta una metodología para la obtención de mapas de turbocompresores, basada en una campaña experimental dividida en varias tipologias de ensayos y seguida de la etapa de modelado. La etapa de modelado se lleva a cabo utilizando modelos de turbocompresores integrales ya desarrollados o disponibles en la literatura. Adicionalmente se aborda la mejora en la precisión de las simulaciones cuando se comparan mapas de turbocompresores postprocesados con mapas puramente experimentales. Aprovechando el modelo de motor 1-D altamente validado y físicamente representativo así como los mapas validados del turbocompresor, se discute cómo las incertidumbres experimentales o las variables "fuera de control" pueden afectar los resultados experimentales. Se propone una metodología para superar este punto desde la perspectiva del modelado. Lo anterior permite realizar comparativas que en las se analiza exclusivamente el impacto de diferentes tecnologías de turbina o unidades de turbinas. Además, tomando como base el modelo ya desarrollado, es posible explorar diferentes cálculos de optimización, estrategias de control y proporcionar comparaciones de tecnología de turbinas en plenas cargas y cargas parciales de motor en un amplio rango de revoluciones. También se aborda el impacto de la altitud y se evalúan los transitorios de carga para dos tecnologías de turbinas analizadas: VGT y WG. Como conclusión, se demuestra que la tecnología VGT muestra menos limitaciones en condiciones de trabajo extremas, como en la curva de plena carga, donde la tecnología WG representa una limitación en términos de máxima potencia. Las diferencias a plena carga se vuelven aún más evidentes en condiciones de trabajo en altitud. Cuando se trata de cargas parciales, las diferencias en el consumo de combustible son menores, pero potencialmente beneficiosas para los VGT. / [CA] S'espera que la nova generació de motors d'encesa per espurna representi la major part del mercat en el context de la propulsió de vehicles amb o sense hibridació. No obstant això, la tecnologia actual encara té reptes crítics per davant per complir amb els nous estàndards d'emissions de CO2 i contaminants. Conseqüentment estan sorgint noves tecnologies per millorar l'eficiència dels motors i que aquests compleixin amb les noves normatives anti-contaminació. Entre d'altres, una de les tendències més seguides en l'actualitat és la reducció de grandària dels motors, concepte conegut com "downsizing", sota la tècnica de la turbosobrealimentación. Les noves tecnologies de turbocompressors, com les VGT, es comencen a considerar per la seva aplicació en les exigents condicions de funcionament dels nous motors d'encesa per espurna. En aquest treball, a partir de dades experimentals obtingudes a la sala d'assajos de l'motor, es proposa una metodologia de calibratge del model complet de motor 1-D: es realitza una anàlisi teòrica dirigit a assegurar el control total sobre qualsevol aspecte de la simulació. En altres paraules, el model de motor 1-D es va ajustar completament respecte a les dades experimentals del motor. A més, es demostra la necessitat del posprocesamiento i validació de dades experimentals relacionats amb mapes de turbocompressors, ja que es requereix desacoblar fenòmens com la transferència de calor i les pèrdues per fricció dels denominats mapes experimentals de turbocompressors. D'acord amb això, es presenta una metodologia per a l'obtenció de mapes de turbocompressors, basada en una campanya experimental dividida en diverses tipologies d'assajos i seguida de l'etapa de modelatge. L'etapa de modelatge es porta a terme utilitzant models de turbocompressors integrals ja desenvolupats disponibles a la literatura. A més a s'aborda la millora en la precisió de les simulacions quan es comparen mapes de turbocompressors postprocessats amb mapes purament experimentals. Aprofitant el model de motor 1-D validat i físicament representatiu així com els mapes validats del turbocompressor, es discuteix com les incerteses experimentals o les variables "fora de control" poden afectar els resultats experimentals. Es proposa una metodologia per superar aquest punt des de la perspectiva de la modelització. L'anterior permet realitzar exclusivament la comparació de tecnologies / unitats de turbines. A més, prenent com a base el model ja desenvolupat, és possible explorar diferents càlculs d'optimització, estratègies de control i proporcionar comparacions de tecnologia de turbines a càrregues completes i parcials del motor en un ampli rang de revolucions del motor. També s'aborda l'impacte de l'altitud i s'avaluen els transitoris de càrrega per a dues tecnologies de turbines analitzades: VGT i WG. com a conclusió, es demostra que la tecnologia VGT mostra menys limitacions en condicions de treball extremes, com en la corba de plena càrrega, on la tecnologia WG representa una limitació en termes de màxima potència. Les diferències a plena càrrega es tornen encara més evidents en condicions de treball en altitud. Quan es tracta de càrregues parcials, les diferències en el consum de combustible són menors, però potencialment beneficioses per als VGT. / [EN] The new generation of spark ignition (SI) engines is expected to represent most of the future market share in the context of power-train with or without hybridization. Nevertheless, the current technology has still critical challenges in front to meet incoming CO2 and pollutant emissions standards. Consequently, new technologies are emerging to improve engine efficiency and meet new pollutant regulations. Among others, one of the most followed trends is engine size reduction, known as downsizing, based on the turbocharging technique. New turbocharger technologies, such as variable geometry turbines (VGT), are evaluated for their application under the demanding operating conditions of SI engines. In this work, from experimental data obtained in an engine test cell, a 1-D complete engine model calibration methodology was conducted: a theoretical analysis aimed at ensuring full control on any aspect of the simulation. In other words, the 1-D engine model was fully fitted with respect to the experimental engine data. Furthermore, it is evidenced the requirement of post-processing and validating the experimental data dealing with turbocharger maps, since phenomena such as heat transfer and friction losses are required to be decoupled from the so-called experimental turbocharger maps. Accordingly, a methodology for turbocharger maps obtention is presented, based on an experimental campaign divided into several test typologies and followed by the modelling stage. The modelling stage is carried out making usage of already developed integral turbocharger models available in the literature. Additionally, the improvement in the accuracy of the simulations when post-processed turbocharger maps are compared against purely experimental maps is addressed. Taking advantage of the highly validated and physically representative 1-D gas-dynamics engine model and turbocharger validated maps, it is discussed how experimental uncertainties or "out-of-control" variables may impact the experimental results. A methodology is proposed to overcome this point from the modelling perspective. The previous allows performing exclusively turbine technologies/units comparison. In addition, taking as a basis the already developed model, it is possible to explore different optimization calculations, control strategies and provide turbine technology comparisons at engine full and partial loads in a wide range of engine speed. Also, the altitude impact is addressed and load transients are evaluated for two analysed turbine technologies: VGT and WG. In all, it was found that VGT technology shows fewer limitations in extreme working conditions, such as full load curve, where the WG technology represents a limitation in terms of the maximum power output. Full load differences become even more evident in altitude working conditions. When it comes to partial loads, differences in fuel consumption are minor but potentially beneficial for VGTs. / Gómez Vilanova, A. (2022). Modelling and analysis methodology of SI IC engines turbocharged by VGT [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181929

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